Source/JavaScriptCore/dfg/DFGDesiredGlobalProperties.cpp

/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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#include "config.h"
#include "DFGDesiredGlobalProperties.h"

#if ENABLE(DFG_JIT)

#include "CodeBlock.h"
#include "DFGCommonData.h"
#include "DFGDesiredIdentifiers.h"
#include "DFGDesiredWatchpoints.h"
#include "JSGlobalObject.h"

namespace JSC { namespace DFG {

bool DesiredGlobalProperties::isStillValidOnMainThread(VM& vm, DesiredIdentifiers& identifiers)
{
    bool isStillValid = true;
    for (const auto& property : m_set) {
        auto* uid = identifiers.at(property.identifierNumber());
        JSGlobalObject* globalObject = property.globalObject();
        {
            SymbolTable* symbolTable = globalObject->globalLexicalEnvironment()->symbolTable();
            ConcurrentJSLocker locker(symbolTable->m_lock);
            if (!symbolTable->contains(locker, uid))
                continue;
        }
        // Set invalidated WatchpointSet here to prevent further compile-and-fail loop.
        property.globalObject()->ensureReferencedPropertyWatchpointSet(uid).fireAll(vm, "Lexical binding shadows an existing global property");
        isStillValid = false;
    }
    return isStillValid;
}

void DesiredGlobalProperties::reallyAdd(CodeBlock* codeBlock, DesiredIdentifiers& identifiers, WatchpointCollector& collector)
{
    for (const auto& property : m_set) {
        collector.addWatchpoint([&](CodeBlockJettisoningWatchpoint& watchpoint) {
            {
                ConcurrentJSLocker locker(codeBlock->m_lock);
                watchpoint.initialize(codeBlock);
            }
            auto* uid = identifiers.at(property.identifierNumber());
            auto& watchpointSet = property.globalObject()->ensureReferencedPropertyWatchpointSet(uid);
            ASSERT(watchpointSet.isStillValid());
            watchpointSet.add(&watchpoint);
        });
    }
}

} } // namespace JSC::DFG

#endif // ENABLE(DFG_JIT)